creating error bars on numbers 09

I'm new to Numbers and I'm trying to draw error bars on my scatter graph.
To draw the graph, I clicked on the chart button, chose scatter graph and just altered the info in a table that popped up to make my chart.

To draw error bars, I went to the chart inspector and clicked on the series tab. I know I need to click on the Advanced button but I can't click it and the data section is empty. I can't click on that either and I can't figure out what I'm doing wrong.